<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<input type="button" value="按钮" onclick="f4()">
<script>
  function f1() {
    console.log("f1");
  }
  f1();

  function f2(name,age) {
    console.log(name+":"+age);
  }
  f2("刘大海",23);

  function f3() {
    return "sb";
  }
  console.log(f3());

  function f4(x,y) {
    return x+y;
  }
  console.log(f4(3,4));

  let f5 = function (x,y){
    return x*y;
  }
  console.log(f5(3,4));

  let f6 = new Function("x","y","return x*y")
  console.log(f6(3,4));

</script>
</body>
</html>